Conventional folding bed frames are relatively heavy and awkward. FIG. 1 (prior art) shows the structure of a conventional folding bed frame including a mattress frame 1 and support legs 2. Mattress frame 1 can be folded in half. The plurality of support legs 2 are pivotally connected under the mattress frame 1. In use, a mattress (not shown) is placed on the mattress frame 1. This structure of the folding bed frame must possess a certain level of bearing strength because the mattress frame 1 must support the mattress. In order to provide bearing strength, mattress frame 1 is made with relatively thick cross-bars and thinner longitudinal bars. The thick cross-bars have relatively large intervals between them, whereas the thinner longitudinal bars are spaced at relatively small intervals. The thick cross-bars and the thinner longitudinal bars are both welded to mattress frame 1. Although the bed frame of FIG. 1 provides stable support for a mattress, the bed frame is awkward and bulky. Because this type of bed frame is typically made of metal, the crossed design of the thick cross-bars and the longitudinal bars increases the weight of the bed frame even further. Especially in the case of a double bed that supports a queen or king size mattress, the bed frame is even more awkward and difficult to carry and transport.
In addition, the bed frame of FIG. 1 is not adaptable to different mattress sizes. Even a conventional bed frame that is sized for either a single bed or a double bed does not accommodate the various dimensions of the single and double mattresses, such as single, twin, full, double, queen, king and California king. A different bed frame size must be manufactured to accommodate each different mattress dimension. Because the bed frame of FIG. 1 cannot be standardized to fit multiple mattress dimensions, the manufacturing cost of the various sizes of the bed frame is increased.
A bed frame is sought that is lighter and less awkward than the conventional bed frame and that can accommodate multiple mattress dimensions. In addition, a folding bed frame is sought that can replace a conventional box spring.